A system for supplying air to the interior of a shoe, which comprises a shell and a gaiter, which is pivoted to the shell and pivotally movable in the longitudinal direction of the shoe is disclosed. An air-handling device is mounted on the shell of the shoe and is connected to actuating means which are operable to cause the air-handling device to pump air. The actuating means are connected to the gaiter and are moved by the pivotal movement of the gaiter.
This invention relates to a system for supplying air to the interior of a shoe or boot, particularly of a skiing boot for Alphine skiing, which shoe comprises a shell and a separate gaiter, which is pivoted or hinged to the shell. An air-handling device is mounted on the shell of the shoe and is operable by the gaiter as the latter is pivotally moved relative to the shell of the shoe.
In the early times of skiing, the skiing boot had only clothing functions and was intended to improve the ability of human beings to withstand changing climatic environmental conditions, particularly to shield against low temperatures and moisture. It must also be borne in mind that the generation of heat and the production of sweat by a human being changes continually in dependence on day-to-day changes of the climate and weather and in dependence on the nature of the activity performed and the effort required. A shoe will not give its wearer a comfortable feeling unless it can balance the external and internal influences in such a manner that a temperature of 28.degree. to 34.degree. C. and a relative humidity of 50 to 70% are maintained at the foot. As the design of the shoe and the materials used to make it were formerly selected in view of these requirements, the boots for Alpine skiing consisted mainly of leather, which is a natural product and provides for an adaptation to the shape of the foot and to the above-mentioned conditions. As the skiing techniques were improved, the functions which were significant for the skiing technique became more important in the design of skiing boots. The desire for an improved lateral stability and the use of different binding systems have resulted in the use of different materials, which involve different manufacturing technologies.
In one or two operations, the shell and the gaiter are made from polymers by means of an injection molding machine and the two parts are then joined by suitable methods (riveting). An inner shoe is provided for adaptation to the foot. The interior padding sometimes contains a flowable material, or a good fit is ensured by adaptable systems, which are connected to hydraulic cushions. The adaptable system which has met with the widest acceptance is the foamed inner shoe, which comprises a material that is tolerated by the skin (leather, Helanca and the like) and coated with plastic material, which is provided with a layer of foamed plastic material, which consists mainly of integral polyurethane foam.
Only the layer which is close to the skin consists of leather or the like. The externally disposed plastic materials are moisture-impermeable and highly heat-insulating so that they inhibit a removal of moisture and heat from the layers that are close to the skin. As a result, the climate in the shoe changes quickly. As the moisture content increases, the heat insulation decreases and the skiier has the distinct feeling of moisture and cold.
In this connection it has already been proposed to provide the shoe at its instep portion or sole with bellows, which are operated by the motions performed by the foot in the shoe during walking and which by means of hoses deliver fresh air into the shoe (German Patent Specification No. 531,997; German Early Disclosure No. 1,679,592). Such devides can only be used if the shoe is larger than would otherwise be required so that the foot can move in the shoe so as to operate the bellows. That concept cannot be used with skiing boots, where an exact, tight and immovable fit of the shoe on the foot is most important.
In French Patent Specification No. 1,598,123 it has been suggested to provide in the heel of the shoe a piston pump having an axis which extends in the longitudinal direction of the shoe. The piston is reciprocated by the movements of the shoe to various inclined positions during walking. Such pumps have only a low capacity and the motion of the piston can easily be obstructed by an ingress of dirt so that the pump will soon be inoperative. Besides, such pumps cannot be used in skiing boots because the skiing boot is rigidly connected to the ski so that it cannot change its position so as to reciprocate the pump piston.
U.S. Pat. No. 3,273,264 discloses a battery-operated fan, which is provided in the heel of the boot. That concept is expensive and the fan is unreliable in most cases and has only a low capacity. Besides, the life of a battery set is much too short for the use of such fans in skiing boots and sports shoes.
Austrian Patent Specification No. 325,458 discloses an air-supply system comprising pumping means which consist of a bellows provided adjacent to the instep portion of the shoe. But the displacement which can be imparted to said bellows at the instep portion is very small so that said device had apparently only a very low air-handling capacity. Besides, the bellows was not operative unless the shoe or its parts consisted of very hard material, such as metal or stiff plastic material. Owing to requirement for skiing boots having very stiff parts, the subject matter of the last-mentioned Austrian patent specification cannot be used in conventional skiing boots.
U.S. Pat. No. 2,716,293 discloses also a shoe which is supplied with air by an air-handling device provided at the instep portion of the shoe. A forward movement of the lower leg will always involve a lowering of the ankle joint; these two movements result in mutually opposite changes of the volume of the bellows, which constitutes the air-handling device and is filled with a porous spongy mass. By said movements, the bellows is compressed adjacent to the lower leg and permitted to expand adjacent to the angle joint so that an undefined, very small volume of air is delivered. Besides, in that shoe the air is sucked from the interior of the shoe and blown off to the outside. Owing to the bone structure of the foot, that shoe is not capable of handling air at a rate which is sufficient for maintaining a pleasing climate at the foot.
U.S. Pat. No. 3,029,530 discloses a shoe which has a bellows-like, hollow heel. Air is supplied to the interior of the shoe as the foot performs a walking motion, by which the heel is compressed and released in alternation. This obviously results in a change of the height of the wedge-shaped heel so that the position of the heel of the foot relative to the supporting surface is changed. Such shoes cannot be used as skiing boots because the skiing boot is rigidly held in the binding so that the heel of the boot cannot and must not be deformed. In the system according to the invention the rigid hollow heel is only a housing, which contains the parts of the air-handling device, which are moved by the lower leg, and the air conduits.
U.S. Pat. No. 3,180,039 discloses a hollow insole having a heel portion which constitutes a bellows whereas the remaining portion of the sole is formed with air exit holes. Such an insole may be useful in shoes for walking and in training shoes, in which the foot has a relatively large freedom of movement so that the foot can directly operate the bellows in the shoe. But such a vertical movement of the foot in a skiing boots prohibited by the safety standards which are in force. Besides, such insole permits only a circulation of air in the shoe rather than a supply of fresh air.
The air-supplying devices described in the two U.S. patents mentioned last are inconsistent with the requirements to be met by skiing boots from the orthopedic aspect.
In order to avoid all the above-mentioned disadvantages of the known shoes it is proposed by the invention that a system of the kind described first hereinbefore should be provided with actuating means, which act on the air-handling device and are connected to the gaiter. The use of such actuating means provides for a greater latitude as regards the selection of the location of the actual air-handling means proper.